[Potentiality of synchronous fluorescence technology for determination of reconstituted milk adulteration in fresh...

In the present research, synchronous fluorescence technique was used for qualitative and quantitative detection of re- constituted milk mixed into two kinds of milk samples, raw milk and pasteurized milk, respectively. The total accuracy of sample was used to evaluate the performance of the qualitative discrimination models. The correlation coefficient (r), the root mean square error of correction (RMSEC) and the root mean square error of prediction (RMSEC) were used to evaluate the perform- ance of the quantitative analysis models. The constant wavelength difference (Δλ) between the excitation and emission scanning was determined to be 80 nm from three-dimensional fluorescence spectrum of milk. The total discrimination accuracy was 100% by partial least squares discrimination analysis (PLS-DA) for raw milk, pasteurized milk and reconstituted milk samples. When checking whether the raw milk and pasteurized milk were mixed with reconstituted milk, the total accuracy of calibration samples was 100% and the accuracy of prediction samples was 75% and 81.25%, respectively. The effects of qualitative discrimination models were satisfactory. The PLS regression was used for quantitative analysis of the reconstituted milk content mixed in raw milk and pasteurized milk. The correlation coefficients of actual values versus predicted values were 0.911 2 and 0.911 2, re-spectively. The RMSEC was 0.042 2 and 0.0384, respectively. The RMSEP was 0.054 8 and 0.057 5, respectively. The cor- relation coefficients of quantitative analysis models could reach up to 0.9. The results showed that synchronous fluorescence technology could be applied for rapid detection of reconstituted milk mixed in fresh milk